1. Field of the Invention
This invention relates generally to spinal surgery, and more particularly to devices for stabilization of the spine in association with placement of an inter-body construct for interbody fusion or the like.
2. Description of the Prior Art
Varieties of inter-body fusion devices are widely used following partial or total discectomies, for stabilization of the spine at the site. Some stabilization devices are anchored to the pedicles. With several systems, the use of the pedicles requires screws or other anchorage devices that occupy significant space and involve muscle dissection and associated work time for implantation. We believe that such elaborate apparatus and procedures are unnecessary in many instances.
Breard et al. U.S. Pat. No. 5,011,484 issued Apr. 30, 1991 discloses an artificial ligament used with an elongate insert. A couple of types of systems, one including rods and another including inextensible strips or inextensible bands, are mentioned as background in U.S. Pat. No. 5,725,582 issued Mar. 10, 1998 to Bevan et al. One such mentioned system is to loop inextensible flexible members directly around spinous processes. The Bevan et al. patent discloses a proposed simplification of the loop procedure, by simply winding the band around spinous processes of adjacent vertebrae as in FIGS. 1 and 2 of that patent, and then tensioning and crimping them. Bevan et al. shows other versions which involve pedicle screws and hooks. The Howland et al. U.S. Pat. No. 5,496,318 uses an arrangement mounted on spinous processes and has a retaining belt 124. Lumb et al. U.S. Pat. No. 3,648,691 uses flexible multi-apertured straps 28 clamped on opposite sides of spinous processes. Vinylidene flouride is given as an example of the strap material and is said to be preferred over machined metal straps. The Kapp et al. U.S. Pat. No. 4,554,914 discloses a pair of elongate plates 28 and 30 clamped onto the spinal processes by bolts through holes drilled in the spinal processes. The Samani U.S. Pat. No. 5,645,599 employs a U-shaped body preferably made of titanium forged in one piece and having upper and lower generally U-shaped brackets with holes therein. The brackets are receivable on spinous processes of adjacent vertebrae and have holes therein to receive bone screws or spikes engaged in the spinous processes and crimped in the holes to anchor the implant thereon.
In our view, and to various degrees, these systems involve one or more of a variety of shortcomings such as size, the necessity of large incisions, difficult manipulation, difficult or excessive drilling or sawing of bone, and permanence and reliability of fixation in association with anterior lumbar interbody fusion (ALIF) procedures. The present invention is directed to overcoming one or more shortcomings encountered with current fixation devices and systems following such procedures.